Cryptography is faster on a GPU than a CPU, if it is programmed. It is faster on an ASIC than a GPU, but to do that the algorithm that has to be programmed and designed / manufactured in hardware.

Feathercoin deliberately moved to Neoscrypt cryptographic alogorythm because it takes more memory to run than the Bitcoin or Litcoin ASICs, and therefore could only be run on a CPU. Feathercoin did not move to Neoscrypt until a GPU version was programmed, in this case paid for by FTC admin (@Calum).